**2.1 Acclimatization**

In the acclimatization step, soil sludge containing mixed culture from soil (MCS) will be collected from banana plantation soil using polyvinyl chloride pipe in 10 cm depth from surface to make sure the anaerobic mixed culture available in the sample. The end of the pipe is then closed with rubber stopper and need to be process in 4 hours after collection was made.

Subsequently, 20 ml of the soil sludge is put into each of 20 serum bottles that contained 20 mg of the banana stem waste (BSW). The bottle is then closed with bottle cap or rubber stopper and flushed with nitrogen for 5 minutes. The flushed bottle is then incubated in anaerobic container in ambient temperature (28oC to 30oC) and dark condition for a month. Then, the content in all serum bottles are put into 1 liter anaerobic container which contained of 10 g of BSW. The 1 litre anaerobic container is then closed and flushed with nitrogen for 5 minutes and left for incubation in ambient temperature (28oC to 30oC) for two months.

Afterward, the materials in the 1 litre anaerobic container are put into two anaerobic container (5 litres) which each of container contained 50 g of BSW. It was found by the inventors of the present invention that acclimatization increased the microbe amount in reactor.

Subsequently, the acclimatized MCS will be used as inoculum for biogas production. Biogas production will be done in 10 L anaerobic fed-batch bioreactor with gas outlet (Fig. 1). Bioreactor equipped with temperature controller and agitator to ensure the inoculum and BSW mixed evently. To maintain anaerobic condition in the reactor nitrogen will be purged everytime the inlet and outlet were done. 5000 mg/l inoculum mixed with BSW at HRT of 12 d and OLR 1.5 gTS/l.d and ambient temperature (28oC to 30oC) for biogas production.

Thus, by first calculating the value of B0, the graph of θ versus B/(B0−B) produces a straight line with an intercept of 1/μmax and with a slope of K/μmax. To obtain the parameter B0 one

Since B is the methane production per gram of added COD, the volumetric methane

The objective of the present study is to develop kinetic parameters for two-stage biogas

In the acclimatization step, soil sludge containing mixed culture from soil (MCS) will be collected from banana plantation soil using polyvinyl chloride pipe in 10 cm depth from surface to make sure the anaerobic mixed culture available in the sample. The end of the pipe is then closed with rubber stopper and need to be process in 4 hours after collection

Subsequently, 20 ml of the soil sludge is put into each of 20 serum bottles that contained 20 mg of the banana stem waste (BSW). The bottle is then closed with bottle cap or rubber stopper and flushed with nitrogen for 5 minutes. The flushed bottle is then incubated in anaerobic container in ambient temperature (28oC to 30oC) and dark condition for a month. Then, the content in all serum bottles are put into 1 liter anaerobic container which contained of 10 g of BSW. The 1 litre anaerobic container is then closed and flushed with nitrogen for 5 minutes and left for incubation in ambient temperature (28oC to 30oC) for two

Afterward, the materials in the 1 litre anaerobic container are put into two anaerobic container (5 litres) which each of container contained 50 g of BSW. It was found by the inventors of the present invention that acclimatization increased the microbe amount in

Subsequently, the acclimatized MCS will be used as inoculum for biogas production. Biogas production will be done in 10 L anaerobic fed-batch bioreactor with gas outlet (Fig. 1). Bioreactor equipped with temperature controller and agitator to ensure the inoculum and BSW mixed evently. To maintain anaerobic condition in the reactor nitrogen will be purged everytime the inlet and outlet were done. 5000 mg/l inoculum mixed with BSW at HRT of 12 d and OLR 1.5 gTS/l.d and ambient temperature (28oC to 30oC) for biogas

� �� � �

���������� (16)

���������� (17)

B=B� �� � �

� <sup>=</sup> ����

uses the following equation, which is easily derived from Eq. (14):

δ = ���

δ has the dimensions of volume methane per volume digester per unit time.

production rate (δ) equals B multiplied by the loading rate:

production using banana stem waste as substrate.

**2. Materials and methods** 

**2.1 Acclimatization** 

was made.

months.

reactor.

production.

Where

Fig. 1. Two-stages biogas production system
